Yosoo 10000# Grit Polishing Sharpening Stone Knife Sharpener Whetstone Oilstone Block The stone is for Polishing and Sharpening Can be used for mirror surface,mirror finish Application: Mainly applied in instrument industry,Precision parts,micro cutting tools,precious stone,Measuring It's Uniform meticulous organization ,Consists of Fine sand, High hardness and Long service life fine-grained whetstone lubricated with oil, used for fine sharpening